Hey Xzamplez,
I can’t think of any forge maps I have played in Halo 5… I remember playing them in Halo 3, Halo 4, Halo Reach, H2A frequently though. I know in Halo 3 there were some incredible maps (I think of Onslaught, Amplified, etc.)… Halo Reach was Sanctuary, The Pit, and quite a few more… Halo 4 had quite a few tested maps I remember playing, although the game never really got going. I come from a competitive player point of view… if it wasn’t played at MLG Events, Gamebattles, etc, I wasn’t playing it… so I guess the equivalent to that now is HCS playlist… Having not played the maps much in Halo 5, I’m not sure how they run, I know after competing on forge maps in the old games, some would have severe FPS drops when scoping in or playing splitscreen (not that you can do that later now)… This was a major issue (didn’t happen in Halo 3 I don’t think, just H2A, Reach, H4?)
I know some people may not want remakes… For instance, Reach, H2A, and H4 were all trying to incorporate H2/H3 map remakes (which I personally am all for because I think H3 had the best maps in the history of Halo for a game’s variety)… but with the new introduced movements and for just the sole purpose of creating a new era, it would be ideal to not reuse the maps that we not only have already had, but have already reused.
Now when it comes to answering your question a bit more directly, I think that a great way to try to get maps recognized by 343i is to get them recognized by the community more first… This could be through the forums, this could be through customs, etc… I know I learned more about maps that weren’t in the competitive playlist from running pick-up games, random 8s, scrims, etc. with teams in custom game lobbies throughout Halo 3, Reach, 4, H2A, etc… People simply saying, “Hey, this map is in testing still… people are trying to get this to be added to the competitive map pool, do you guys wanna play it and see how it feels? You can send a message to the creator about what you think.”… and hey, it worked sometimes… popularity grew, some maps were added, some weren’t, it provided valuable information to the map creator, etc… There are other routes I suppose as well… When it comes to BTB and other playlists, I have no idea because I don’t load into those gametypes ever…but I’m sure there are routes somewhere! 